The present invention relates to a pipe coupling for connection to a pipe end of a plastic pipe, said pipe preferably being used in tap water or heating installations. The coupling includes an inner sleeve for insertion into said pipe end into abutment with the inner surface thereof, and an outer sleeve which is intended to lie in abutment with the outer surface of said pipe end and which includes a slot-like opening and means for adjusting the size of said opening.
A metal pipe coupling for interconnecting cross-linked polyethylene pipes installed in hot and cold water systems and in central and district heating pipe systems is known to the art from U.S. Pat. No. 4,039,212. This pipe coupling is of the kind described in the introduction and is available in various versions designed to handle different pipe pressures, However, because of successively stricter approval standards ordained by the relevant authorities, decreeing that the coupling joint shall be stronger than the pipe itself, has meant that these pipe couplings are unable to meet satisfactorily certain test requirements, such as pullout tests, load tests and other functional tests carried out in practice. A common drawback with these earlier known versions is that the couplings do not exert an evenly distributed clamping force around the full periphery of the pipe, that the couplings cannot be adjusted uniformly to provide a tight and sealed join, and that they require detailed fitting instructions and continuous monitoring of the tightening force.
An object of the present invention is to provide a pipe coupling which, in one and the same version, can manage different pipe pressures, which will fulfill the load and function requirements applicable to these types of couplings, which can be fitted easily and quickly, and which does not require the use of large and special tools in order to fit the coupling.
This object is achieved in accordance with the invention, with a coupling that has the features set forth in the accompanying claims,